Delta 4 Heavy Launch – August 28, 2013
A Delta 4-Heavy, made by United Launch Alliance, is one of the largest rockets launched from Vandenberg Air Force Base, lifted off Wednesday morning at 11:03. PST from Vandenberg Air Force Base’s Space Complex 6.
The clandestine satellite payload is for the National Reconnaissance Office satellite which was placed into a polar orbit. Space Complex 6. The 27 story high launch complex was initially built to support space shuttle missions and was upgraded to handle today’s launch.
Today’s launch will use a new strategy to reduce the hydrogen flames generated during startup of the three Aerojet Rocketdyne RS-68 main engines on the launch vehicle. One engine on the massive 23 story high rocket will ignite two seconds before the other two engines instead of all three igniting at the same time.
During a Delta 4 launch in 2011 the ignition plume from the three engines ignited external insulation material as the vehicle lifted off and cleared the pad. The flames extinguished a few seconds later and the mission payload was successfully placed in orbit.
Staggering the ignition of the engines is being used to prevent a similar incident and will not alter the engines' operations during flight. As of 11:10 launch status was blacked out.